Noiseless slate



(No Model.)

J. RIDGE.

NOISELESS SLATE.

Patented June 5, 1883.

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' UNITED STATES PATENT OFFICE.

JOSEPH RIDGE,'OF CHICAGO, ILLINOIS.

NOISELESS SLATE.

SPECIFICATION forming part of Letters Patent No. 278,744, dated June 5,1883. Application filed March 7, 1883. (No model.)

To all whom it may concern:

Be it known that I, JOSEPH RIDGE, of Chi cago, county of Cook, and Stateof Illinois, have invented new and useful Improvements in NoiselessSlates, of which the following is a full and complete description,reference being had to the accompanying drawings.

My invention relates to a method of muffling' slates, wherein the clothor strip is so secured in the frame that a better cushion or moredeadened effect is secured than by the usual method of drawing the clothtightly on the frame or supplemental strip. My invention also relates tocheapening the operation of muffling and to giving the slate at neaterappearance.

\Vith reference to the drawings, Figure 1 represents the slate with aportion broken away. Fig. 2 is a section of the frame before the muffleris applied. Fig. 3 is a cross-section of the finished slate throughbroken line, Fig. l; and Fig. 4 is an edge elevation.

A represents the slate proper. B is the frame. a represents notches orrecesses along the outer margin of the frame. 0 represents themuffling-strip, of cloth or other pliable and noiseless material, and 1)represents keys or wedges.

As perhaps the best method of securing the keys in the notches,thelatter are dovetailed. The mufliing strip is somewhat greater inwidth than the thickness of the frame, and is drawn tightly around theouter surface of said frame, being forced at intervals into each notchor recess, where it is secured by keys I). The strip 0 being wider thanthe thickness of the frame, it is so adjusted thereon that its edgesproject on each side, forming a narrow pliable cushion or rib, by whichthe frame is protected from contact with the desk, and the consequentnoise avoided. As the most rapid and easy manner of inserting the keys,the latter are made of strips of sheet metal coveredwith cloth and cutinto proper size. They may then be curved and shortened, so they willenter the cor serpentine directions outside or narrowest part of thenotch, and, be?

ing forced in on strip C, may be straightened by pressure and thusfirmly secured, at the same time securing said strip 0.

Solid or inflexible keys may of course be driven into the notch at theside of the frame, the muffling-strip being first pressed down into thenotch; or said strip 0 may be so cured in the notches in any othermanner, the latter serving to secrete said fastenings and to preventtheir contact with the disk.

It is evident that the muffling-strip being drawn tightly in circuitousor zigzag directions around the frame, and its central portion beingsecured as with the keys, the tension prevent-s the edges of said stripfrom being crushed or flattened down to remain so, but will stand out,forming the desirable cushion or support that renders the slate morenoiseless than when the covering is drawn tightly and flatly on theframe.

The notches or recesses may of course be longer and located fartherapart than relatively shown in the drawings, with substantially the sameeffect. The result of the series of notches with the strip c inserted isto give the frame a scalloped appearance, thus adding to its neatness.

Having thus fully tion, what I claim, and desire to secure by LettersPatent, is-

1. The slate-frame provided with notches or recesses around its outersurface, in combination with the muffling-strip G and keys I), or otherfastening devices, substantially as and for the purpose specified.

2. In combination with a slate-frame, the band or ribbon like strip 0,secured in zigzag by removing sections of said frame and clamping saidstrip therein, substantially as and for the purpose set forth.

JOSEPH RIDGE. \Vitnesses:

Gno. B. KENYON, FRANK WARNER.

